如何使用HttpClient w.post发送数据和图像
本文关键字：数据 图像 post 何使用 HttpClient | 更新日期: 2023-09-27 18:29:53
我需要使用HttpClient执行一个post方法，并在我的PHP web服务中捕获它。
第一次，我开始使用FormUrlEncodedContent，没关系，我的web服务收到了这些数据。但现在我需要用户捕获一个图像并将其放入字节数组中。
为此，我想MultipartFormDataContent就是这里的英雄。这就是我的
Dictionary<string, string> @params = new Diction ...
byte[] imageData = ...
var requestContent = new MultipartFormDataContent();
requestContent.Add(new FormUrlEncodedContent(@params));
requestContent.Add(new ByteArrayContent(imageData));
HttpClient client = new HttpClient();
HttpResponseMessage response = await client.PostAsync(request, requestContent);
response.EnsureSuccessStatusCode();
string responseBody = await response.Content.ReadAsStringAsync();
但当我收到回复时，我会得到以下信息：
responseBody"
''n警告：文件上载Mime标头在未知行0
''n｛''"…"字符串中乱码
我不知道php代码还是我的c代码中有问题。
我们也遇到了类似的问题，我们不得不去掉HttpClient，因为它不是很灵活。在我们的案例中，我们不得不将多个文件上传到服务器。我们最终使用了WebRequest。工作代码如下。看看PostMultipart函数-其他的都是助手。
public class UploadFile
{
public UploadFile(Stream data, string fieldName, string fileName, string contentType)
{
this.Data = data;
this.FieldName = fieldName;
this.FileName = fileName;
this.ContentType = contentType;
}
public UploadFile(string fileAbsPath, string fieldName, string fileName, string contentType)
: this(File.OpenRead(fileAbsPath), fieldName, fileName, contentType)
{
}
public UploadFile(string fileAbsPath, string fieldName, string contentType)
: this(fileAbsPath, fieldName, Path.GetFileName(fileAbsPath), contentType)
{
}
public UploadFile(string fileAbsPath)
: this(fileAbsPath, null, Path.GetFileName(fileAbsPath), "application/octet-stream")
{
}
public Stream Data { get; set; }
public string FieldName { get; set; }
public string FileName { get; set; }
public string ContentType { get; set; }
public DateTimeOffset? CreationDate { get; set; }
public DateTimeOffset? ModificationDate { get; set; }
}
class MimePart
{
private readonly NameValueCollection headers = new NameValueCollection();
private byte[] header;
private Stream data;
public override Stream Data
{
get
{
return this.data;
}
}
public void SetStream(Stream stream)
{
this.data = stream;
}
public NameValueCollection Headers
{
get { return this.headers; }
}
public byte[] Header
{
get { return this.header; }
}
public long GenerateHeaderFooterData(string boundary)
{
var sb = new StringBuilder();
sb.Append("--");
sb.Append(boundary);
sb.AppendLine();
foreach (string key in this.headers.AllKeys)
{
sb.Append(key);
sb.Append(": ");
sb.AppendLine(this.headers[key]);
}
sb.AppendLine();
this.header = Encoding.UTF8.GetBytes(sb.ToString());
return this.header.Length + this.Data.Length + 2;
}
}
private IList<MimePart> GenerateMimePartsList(IEnumerable<UploadFile> files)
{
var mimeParts = new List<MimePart>();
int nameIndex = 0;
// Files data
foreach (UploadFile file in files)
{
var streamMimePart = new StreamMimePart();
if (string.IsNullOrEmpty(file.FieldName))
{
file.FieldName = "file" + nameIndex++;
}
var contentDispositionValues = new List<string>();
contentDispositionValues.Add("form-data");
contentDispositionValues.Add(string.Format("name='"{0}'"", file.FieldName));
contentDispositionValues.Add(string.Format("filename='"{0}'"", file.FileName));
if (file.CreationDate.HasValue)
{
contentDispositionValues.Add(string.Format("creation-date='"{0}'"", file.CreationDate.Value.ToString("R")));
}
if (file.ModificationDate.HasValue)
{
contentDispositionValues.Add(string.Format("modification-date='"{0}'"", file.ModificationDate.Value.ToString("R")));
}
// "form-data; name='"" + file.FieldName + "'"; filename='"" + file.FileName + "'"";
streamMimePart.Headers["Content-Disposition"] = string.Join("; ", contentDispositionValues);
streamMimePart.Headers["Content-Type"] = file.ContentType;
streamMimePart.SetStream(file.Data);
mimeParts.Add(streamMimePart);
}
return mimeParts;
}
public void PostMultipart(Uri uri, IEnumerable<UploadFile> files)
{
var mimeParts = this.GenerateMimePartsList(files);
var boundary = "----------" + DateTime.Now.Ticks.ToString("x");
byte[] footer = Encoding.UTF8.GetBytes("--" + boundary + "--'r'n");
var request = (HttpWebRequest)WebRequest.Create(uri);
request.Method = "POST";
request.ContentType = "multipart/form-data; boundary=" + boundary;
request.ContentLength = mimeParts.Sum(part => part.GenerateHeaderFooterData(boundary)) + footer.Length;
try
{
// Write data
byte[] buffer = new byte[8192];
byte[] afterFile = Encoding.UTF8.GetBytes("'r'n");
using (Stream requestStream = request.GetRequestStream())
{
foreach (MimePart mimePart in mimeParts)
{
requestStream.Write(mimePart.Header, 0, mimePart.Header.Length);
int read;
while ((read = mimePart.Data.Read(buffer, 0, buffer.Length)) > 0)
{
requestStream.Write(buffer, 0, read);
}
mimePart.Data.Dispose();
requestStream.Write(afterFile, 0, afterFile.Length);
}
requestStream.Write(footer, 0, footer.Length);
}
// Get response
using (var response = (HttpWebResponse)request.GetResponse())
{
var responseText = response.ReadAsString();
return;
}
}
catch (WebException webException)
{
this.HandleErrorResponse(webException);
}
finally
{
foreach (var mimePart in mimeParts)
{
if (mimePart.Data != null)
{
mimePart.Data.Dispose();
}
}
}
return;
}